The effects of respiratory muscle strengthening exercise using a sling on the amount of respirationSeu ng-Ju Yi, PT, PhD1), Jin-Seop Kim, PT, PhD2)*1) Department of Physical Therapy, Andong Science College, Republic of Korea2) Department of Physical Therapy, Sunmoon University: 70 Sunmoon-ro, 221 beon-gil, Tangjeong-myeon, Asan-si, Chungnam 336-708, Republic of KoreaAbstract. [Purpose] The purpose of this study was to present aerobic exercise that can be performed together with respiratory muscle strength training and examine whether the vital capacity of individuals can be enhanced when respiratory muscle strength training is conducted together with aerobic exercise. [Subjects and Methods] The subjects were 10 male students and 8 female students. The sling exercise method was used to conduct three types of training to strengthen the muscles around the shoulder joints. A maximal respiratory quotient measurement device was used to measure the vital capacity of the subjects five times. [Results] There was a significant difference in each respiratory training time point compared with before the performance of respiratory training. [Conclusion] This study presented respiratory muscle strength training using a sling as a training method for respiratory training.Key words: Sling, Aerobic exercise, Respiratory(This article was submitted Feb. 25, 2015, and was accepted Mar. 24, 2015)INTRODUCTIONVentilation between air and blood occurs through neuro-logical control of the respiratory muscles1). Muscles related to respiration may be divided into inspiratory and expira-tory muscles. Major muscles engaging in inspiration include the diaphragm and external intercostal muscle, and minor muscles engaging in inspiration encompass the sternoclei-domastoid muscle, scalene muscle, trapezius muscle, pec-toralis major muscle, pectoralis minor muscle, and serratus anterior muscle. These muscles act during forced expiration. Expiratory muscles that do not act in normal respiration but do act in strong respiration include the rectus abdominis muscle, musculus transversus abdominis, external/internal oblique abdominal muscle, and internal intercostal muscle. Weakening of the respiratory system muscles is a risk factor for cardiovascular disease, and these muscles play a role in reducing the pressure of the lower abdomen during respi-ration2, 3). Therefore, it has been reported that respiratory muscle strength training not only improves motor ability but also decreases dyspnea and nocturnal desaturation4). For such a reason, in the clinical field, medical devices are used as interventions to improve the respiratory muscles of patients with chronic obstructive pulmonary disease, asthma, spinal cord injury, and muscle disease. To improve respiration and prevent respiratory diseases, devices such as high-frequency chest wall oscillations devices, flutters, pos-itive-pressure masks, and resistance breathing devices are used. Respiratory muscle training conducted with assistive devices for respiration has brought about improvements in respiratory muscles5, 6). According to recent research, inspi-ratory muscle training using inspiratory resistance devices strengthens inspiratory muscles7), and respiratory training and the strengthening of inspiratory muscles has been shown to improve the quality of life of stroke patients8). Researchers have also reported that assistive devices like balloons may improve the vital capacity of smokers9). However, previous researchers mostly conducted respiratory muscle training using assistive devices, and physical training to strengthen respiratory muscles has been lacking. In actuality, when aerobic exercise was conducted together with breathing exercise, respiratory muscles and pulmonary functions were enhanced10, 11). Therefore, the purpose of this study was to present aerobic exercise that can be performed together with respiratory muscle strength training and examine whether the vital capacity of individuals can be enhanced when re-spiratory muscle strength training is conducted together with aerobic exercise.SUBJECTS AND METHODSThis study was conducted from May 27 to July 26, 2013, and involved 18 undergraduates living in Andong City, Re-public of Korea. The subjects who participated in this study voluntarily participated, and consent to take part in this study was obtained from them. Among the subjects, there were 10 male students and 8 female students. Their average age, height, and weight were 21.5 years old, 168.5 cm, and J. Phys. Ther. Sci. 27: 2121–2124, 2015*Corresponding author. Jin-Seop Kim (E-mail: [email protected])©2015 The Society of Physical Therapy Science. Published by IPEC Inc.This is an open-access article distributed under the terms of the Cre-ative Commons Attribution Non-Commercial No Derivatives (by-nc-nd) License <http://creativecommons.org/licenses/by-nc-nd/3.0/>.Original ArticleJ. Phys. Ther. Sci. Vol. 27, No. 7, 2015212263 kg, respectively. The rate of smokers was 44.44%, and the average duration of smoking was 3.5 years. A maximal respiratory quotient measurement device (Personal Best full range flow meter, Philips Respironice, Parsippany, NJ, USA) was used to measure the vital capacity of the subjects five times—prior to the exercise, two weeks after the exercise, four weeks after the exercise, six weeks after the exercise, and eight weeks after the exercise. The subjects sat in a chair, spread their shoulders, and grabbed the measurement device. Three measured values under the maximal expira-tory condition were averaged. The sling exercise method was used to conduct three types of training to strengthen the muscles around the shoulder joints. The subjects conducted shoulder internal rotation, shoulder external rotation, and push-ups. Figure 1 shows a subject engaging in shoulder internal rotation. As a starting posture, the subjects spread their legs shoulder-width apart and looked straight forward in a neutral position. They then put on a wide sling band around their abdomen with their shoulders spread at 90 degrees and their elbows spread at 90 degrees, conducted external rotation of the shoulders while tilting their bodies forward, and conducted inspiration. Then again in the start-ing posture, the subjects conducted internal rotation of the shoulders and expiration. Figure 2 shows external rotation of the shoulder joints. As a starting posture, the subjects stood on a reference line facing backward with their legs